Evidence of perineural invasion on prostate biopsy specimen and survival after radical prostatectomy.

OBJECTIVE: To better understand relationships between perineural invasion (PNI) and radical prostatectomy outcomes, we examined whether PNI was independently associated with adverse pathologic features and worse survival outcomes after radical prostatectomy.
METHODS: PNI is a routinely reported pathologic parameter for prostate biopsy specimens. We identified 3226 patients undergoing radical prostatectomy for clinically localized prostate cancer at our institution between 1994 and 2010. We used multivariable logistic regression models to examine whether PNI was independently associated with extraprostatic extension, seminal vesicle invasion, and surgical margin status. We used Kaplan-Meier methods and the log-rank test to assess disease-free, prostate cancer-specific, and overall survival according to PNI status. Cox proportional hazards modeling was used to evaluate relationships between PNI and survival outcomes.
RESULTS: PNI was identified in the prostate biopsy specimen in 20% of patients who underwent radical prostatectomy. Patients with PNI were more likely to have adverse pathologic features, including extraprostatic extension, seminal vesicle invasion, and positive surgical margins. Patients with PNI had shorter disease-free, cancer-specific, and overall survival (all log-rank P <.001). After adjustment for adverse pathologic features at radical prostatectomy, PNI was independently associated with disease-free survival (adjusted hazard ratio, 1.45; 95% confidence interval, 1.09-1.92) and overall survival (hazard ratio, 1.57; 95% confidence interval, 1.13-2.18).
CONCLUSION: PNI was independently associated with adverse pathologic features and worse survival outcomes after radical prostatectomy. For these reasons, PNI on prostate biopsy specimens should be considered in prostate cancer treatment decision making and clinical care.